The patient bearing surface of an operating table may be changed in its shape and position by actuating various actuators to set an optimal supporting position for a specific operation or treatment of the patient. In the case of operating tables having multiple joints, the risk of collisions of individual operating table components with one another increases with each adjustment element. Above all, the components leg plate, back plate, table column, or table base are at risk. The user may damage table parts and at the same time also injure the supported patient due to inattention or due to incorrect operation.
To reduce the risk of collisions, sensors can be installed in the operating table to detect the adjustment movements of the table components and relay them to an electronic controller. This controller computes a possible imminent collision or an incorrect setting from the sensor values and stops the adjustment movement if there is a risk of collision, in order to avoid damage to the table or patient.
For certain positions, complete profiles can be preprogrammed or prepared by the user himself, and then retrieved using a single button press. Therefore, personnel time and device setup times may be saved to a substantial extent. In prior art, cable pull potentiometers are used for this purpose, for example, allowing for the detection of the positions of the individual adjustable elements. In general, cable pull potentiometers are used for measuring the vertical and horizontal table positions. However, cable pull sensors are sometimes also used for (indirect) angle detection, since angle sensors often cannot be attached to the rotational axes for reasons of space. The customary cable pull sensors are susceptible to error, however, since the cable, which usually extends in the open and may be readily accessible and exposed to the certain environmental elements, may in the hospital setting become soiled, and is unprotected from mechanical influences, for example, jamming, hooking, or warping.